1. Field of the Invention
This invention relates to a method of manufacturing semiconductor devices, and particularly to a method of manufacturing the electrodes and wiring in a semiconductor integrated circuit.
2. Description of the Prior Art
Heretofore aluminum and polyclystalline silicon have been the most widely used of materials for the electrodes and wiring in semiconductor integrated circuits, but with the use of aluminum miniaturization has been difficult, and with the use of polycrystalline silicon resistance values are high and it has not been possible to give the elements high speed characteristics. For these reasons, metals with a high melting point, such as molybdenum and tungsten or metallic silicides of these (MoSi.sub.2, WSi.sub.2) have recently been studied as materials to replace polycrystalline silicon, and in order to obtain a certain pattern of electrodes and wiring with these, a photoengraving process has been applied.
FIGS. 1(a) to 1(d) show the prior manufacturing process of the wiring portion. In this prior art process, firstly, as shown in FIG. 1(a), a silicon oxide film 2 and a molybdenum film 3 are sequentially formed on a silicon semiconductor substrate 1, and then a resist 4 is formed in a predetermined pattern by means of a photoengraving technique, as shown in FIG. 1(b). Subsequently, with this resist 4 as a mask, the aforementioned molybdenum film 3 is selectively etched, as shown in FIG. 1(c), after which the resist 4 is removed and a desired wiring pattern in the molybdenum film 3 is obtained, as seen in FIG. 1(d).
However, the above described method employs a resist 4 and so necessitates the process of selectively etching the resist 4, and the process of completely removing it, which results in the drawback that the manufacturing process is complicated.